de Miranda, Thiago M.; de Oliveira, Alan R.; Pereira, Juliano R.; da Silva, Jeferson G.; Lula, Ivana S.; Nascimento, Clebio S. Jr.; Denadai, Angelo M. L. published the artcile< Inclusion vs. micellization in the cethylpyridine chloride / β-cyclodextrin system: A structural and thermodynamic approach>, Synthetic Route of 123-03-5, the main research area is complexation micellization cethylpyridine chloride cyclodextrin structure thermodn.
In the present work we have performed a structural and thermodn. characterization of supramol. structures formed by interaction between cetylpyridinium chloride (CPC) surfactant and β-cyclodextrin (βCD), using several phys.-chem. methods. Initially, qual. CPC/βCD interactions in solid state were confirmed by FTIR and TGA/DTA. 2D NMR ROESY experiment showed strong correlations between hydrogens of βCD cavity with aromatic and aliphatic hydrogens of CPC, suggesting the existence of different complexes in solution This information was corroborated by structures assessed by computational approach and stoichiometric coefficient obtained by ITC (N = 1.45). ITC experiments (at constant concentration of CPC) also showed that host-guest complexation occur with very high binding constant (Kb = 38,300.0), and driven by enthalpy and entropy. However, as CPC is an amphiphilic mol., it is able to form micelles at critical micellar concentration close to 1 mM. In presence of βCD, it was observed that micellization was delayed, so that the cmc values increased according to the empiric equation: cmc = 1.02 + 0.5[βCD]. Moreover, thermodn. data obtained by combination of conductometric and isothermal calorimetry titrations showed that the presence of increasing concentrations of βCD causes an increase of free energy of micellization, specially by gradual reduction of entropy of micellization, due to the difficult of micelles encapsulate the inclusion compounds The overall study was rationalized in terms of competition between micellization vs. host-guest complexation.
Journal of Molecular Structure published new progress about Complexation enthalpy. 123-03-5 belongs to class pyridine-derivatives, and the molecular formula is C21H38ClN, Synthetic Route of 123-03-5.